Bridging push-button switch with plastic mating housing portions

ABSTRACT

An interlock type switch in which mating housing portions define a closed interior chamber and clamp projecting terminals. A contact member within the chamber is adapted to bridge the terminals which perform dually as terminals and contacts. An actuator has a sliding mount in one of the housing portions and is externally accessible to raise and lower the contact member. Integrated stud means hold the housing portions in an assembled relation and fix the terminals therein.

United States Patent [191 Smith et a1.

[11] 3,829,633 [451 Aug. 13,1974

[ BRIDGING PUSH-BUTTON SWITCH WITH PLASTIC MATING HOUSING PORTIONS [75]Inventors: Jerry L. Smith, Springfield; Frank F. Powling, Bellefontaine,both of Ohio [73] Assignee: Carlisle Corporation, Cincinnati,

Ohio

[22] Filed: May 2, 1973 [21] Appl. No.: 356,584

[52] US. Cl 200/16 A, 200/166 CT, 200/160 [51] Int. Cl. H01h 13/04 [58]Field of Search 338/184, 199; 200/16 A,

200/159 R, 160, 166 BF, 166 CT [56] References Cited UNITED STATESPATENTS 2,845,608 7/1958 Short ZOO/l6 A 3/1966 Van Der Put 338/1997/1972 Mitchell 200/159 R Primary Examiner-Robert K. Schaffer AssistantExaminerGerald P. Tolin Attorney, Agent, or Firml-Iood & Coffey [5 7]ABSTRACT 7 Claims, 9 Drawing Figures 15,; I m 4/ hirls-4 PATENT En AUG'1 31914 BACKGROUND OF THE INVENTION This invention relates to interlocktype switches of general utility. It has, however, particular althoughnot limited reference to interlock switches as used in riding mowers andlike equipment. Switch devices of that general application are requiredto be weather protected, resistant to misoperation caused by vibrationand unskilled handling, reliable in use and relatively inexpensive ofconstruction. Prior art devices have had limited success in meetingthese requirements. Attempts to impart reliability and long life intheir performance have been accomplished at a sacrifice of simplicityand low cost. Efforts towards simplified design and reduced constructioncosts have produced devices of low reliability susceptible tomisoperation under the relatively rugged imposed operating conditions.

SUMMARY OF THE INVENTION The instant invention has in view an interlockor like switch having relatively few, easily assembled parts which yetlends itself to precise, reliable operation over extended periods oftime and under severe environmental conditions. In a feature of thedevice, terminals by which the device is connected in an electricalcircuit serve dually as switch contacts. A compact, sealed constructionis achieved through use of opposing housing portions which areinterconnected by integrated stud means serving also to anchor theterminals in place. The need for separable connectors is obviated. Thehousing portions define a closed interior chamber containing a bridgemember alternately lifted from and returned to a seat on said terminals.An actuator accessible from the exterior of the switch has a slidingmount in one of the housing portions and projects into the closedinterior chamber variably to position the bridge member. Movements ofthe bridge member and actuator are in a straight line, with the devicehaving in effect but one moving part. Making and breaking of the circuitwhich the switch controls is a quick, positive action occurring in acontrolled environment with minimal opportunity for arcing and excessivecontact wear.

An object of the invention is to provide an interlock or like switch ofgeneral utility and characterized by a simple, compact construction ofhigh reliability.

Another object of the invention is to provide a switch device in whichswitch housing portions cooperate in confining terminal and switchingcomponents and are precisely fit together without need for separableconnectors.

A further object of the invention is to provide a switch device in whichswitch housing portions interfit to provide for straight line motion ofa switch actuator and an associated switch contact, said actuator andcontact constituting a single moving switch component.

Still another object of the invention is to provide a switch device inwhich terminals connecting the device in an electrical circuit servedually as switch contacts.

With the above and other incidental objects in view as will more fullyappear in the specification, the invention intended to be protected byLetters Patent consists of the features of construction, the parts andcombinations thereof, and the mode of operation as hereinafter describedor illustrated in the accompanying drawings, or their equivalentsvReferring to the accompanying drawings wherein is shown one but notnecessarily the only form of embodiment of the invention;

FIG. I is a view in side elevation of an interlock switch in accordancewith the illustrated embodiment of the invention;

FIG. 2 is a top plan view of the switch of FIG. I;

FIG. 3 is a bottom plan view of the switch of FIG. 1;

FIG. 4 is a view in longitudinal section, taken substantially along theline 4-4 of FIG. 2;

FIG. 5 is a view in horizontal section taken substantially along theline 5-5 of FIG. 4;

FIG. 6 is a view in cross section taken substantially along the line 6-6of FIG. 4;

FIG. 7 is a view in cross section taken substantially along the line 7-7of FIG. 4;

FIG. 8 is a detail view, partly in section, of one of the switch housingportions; and

FIG. 9 is a view like FIG. 8, showing another switch housing portion.

Referring to the drawings, an interlock switch in accordance with theillustrated embodiment of the invention includes mating housing portions10 and 11 which, for convenience, will be identified, as illustrated,respectively as upper and lower housing portions. It will be understoodthat the switch is in use oriented in any desired attitude, includingthe reverse of that here illustrated.

Upper housing portion I0 is made of a nonconductive plastic or likematerial and is molded or otherwise formed as a single element. Itincludes a generally rectangular plate portion 12, having taperedrounded ends, from the mid portion of which rises an inverted cup-likeportion 13. The diameter of the cup portion 13 is slightly greater indimension than the width of the plate portion 12. It will be seen thatthe cup portion is so arranged to have its outer wall surface coincidentat one point with one edge of the plate portion, providing thereby thatthe cup wall includes an arcuate segment 20 producing a projection atthe opposite edge of the plate portion 12.

The cup 13 projects above what may be considered an outer or upper face14 of the plate portion 12, in the orientation shown, to define a cavity15 opening at the mouth thereof through what may be considered an inneror lower face 16 of the plate portion. The plate portion 12 is providedwith a recess 17 centered in the face 16, which recess has back and sidewalls which are rectangularly arranged and a front wall includinglateral openings at its dependent edge defined by spaced apart notchesl8 and 19. The latter are separated by an arcuate web portion 21 of theprojection 20 of the wall of the cup 13, being defined thereby at thelip of the cup. Positioned at diametrically opposed locations referencedto the mouth of the cavity I5 and projected outwardly from andperpendicular to the base of the recess 16 are integrally formedstud-like portions 22 and 23. The projected extremities of the studs 22and 23 terminate outwardly of the plane of the plate surface 16.

It is noted that the stud-like projections 22 and 23 are located in themajor axis of the housing portion 10. In the same axis and positionedoutwardly of the stud 22 and 23, in the tapered end portions of theplate portion 12, are respective openings 24 and 25. The material in thebase of the recess 17 is undercut around each of the stud means 22 and23 to form annular grooves respectively'identified by the numerals 26and 27.

The upper housing portion 10, by reason of its configuration, isaccordingly comprised of an inverted cuplike member having laterallyout-thrust wing sections by means of which the switch housing may bemounted in use. The inverted cup member forms a cavity which opens to arecess which circumscribes the mouth thereof, from the base of whichrecess project a pair of diametrically spaced stud means 22 and 23.

The lower housing portion 11 includes a rectangular plate portion 28generally corresponding in configuration to that of the recess 17 in thehousing portion 10. An arcuate cut-out 29 along one marginal edge of theplate portion 28 is shaped to accommodate the web segment 21 formingpart of the wall of the cup 13 of the upper housing element. Nearopposite ends of the plate portion 28, in its major axis, are throughopenings 31 and 32. On what may be considered an upper or inner face 30of plate portion 28, the openings 31 and 32 are respectively surroundedin each case by an annular groove, the grooves being respectivelyidentified by the numerals 33 and 34. Positioning intermediately of theopenings 31 and 32, and projecting outwardly or downwardly of the plateportion 28, is a cylindrical body portion 35. The latter is providedcentrally thereof with a bore 36 terminating at what may be consideredits upper or inner end in a counterbore 37. Lower housing portion 11 ismade of a non-conductive material like that of which the upper housingis made.

Terminals of the switch disclosed are represented by metal plate-likemembers 38 and 39. The members 38 and 39 are identical, each having ablade-like body portion 41 incorporating a co-planar attachment portion42 which projects from one edge thereof. In the bladelike body portion41, toward what may be considered an inner end thereof, is an aperture43 having a diameter corresponding approximately to the outside diameterof the stud means 22 and 23. As will be noted, the body 41 is generallyrectangular, with straight parallel sides. The width of body 41corresponds approximately to the width of one of the notches 18 or 19and is such that with a terminal member inserted through such notch aside edge of the member overlaps a peripheral portion of the mouth ofthe housing cavity 15. The terminal members 38 and 39 are made of arigid material having good electrical conductivity.

An actuator pin 44 also forms part of the disclosed switch. This has adiameter to give it a sliding mount within the bore 36 and includes aflange 45 on what may be considered the inner end thereof. The flange 45has a greater diameter than the body of the pin 44 but its diameter issomewhat less than that of the counterbore 37. In length, the pin 44exceeds the length of the bore 36 and counterbore 37 so that in aninstalled position in the body portion 35 connected integral with theplate portion 28 the pin will project beyond such body portion to eitherend thereof. Pin 44 is made of a nonconductive material which is or maybe the same material of which the housing portions 10 and 11 arefabricated.

Further comprised in the switch is a washer-like member 46. This memberis made of a material which is rigid and durable and which will serve asa good electrical conductor. It will be seen that the outside diameterof the washer-like member exceeds the diameter of the counterbore 37while its inside diameter is such as to relatively loosely passtherethrough a projecting end of pin 44. A compression spring 47 isincluded to seat within and to react upon the upper or base end of thecup 13, which base end incorporates a stud-like protuberance 48projected internally of the spring to center the same and function as aspring guide. As applied, the spring 47 functions, as will be seen, tohave its base end seat upon and bias the washer 46 towards a seat on theflange 45 of pin 44. In this manner there is produced a yielding forceresistant to an axial thrust of the pin 44 in a direction interiorly ofthe cavity 15.

In assembling the components of the switches de scribed, terminalmembers 38 and 39 are placed against the upper or inner face of housingportion 11 in a lateral spaced apart side-by-side relation, withapertures 43 thereof aligning with housing portion apertures 31 and 32.Actuator pin 44 is mounted in bore 36, so oriented that its flange 45 isreceived in the counterbore 37. Washer-like member 46 is then slippedover the short upper end of pin 44 above its flange 45 to seat to theflange. At this point an end of spring 47 is applied thereto. lt will beseen from the drawings that in its application to pin 44 the washer-likemember 46 achieves an overlapping relation to both adjacent side edgesof the terminals 38 and 39, the body portions 41 of which are solidlysupported throughout their width by the underlying face of housingportion 11 to which they are seated.

The sub-assembly comprising the housing portion 11, actuator 44, washer46 and spring 47 as described, is now applied to the upper housingportion 12, to the side thereof including the face 16.1n the course ofsuch movement, the free or projected end of the spring 47 is caused toseat to the base of the inverted cup portion 13, around the protuberance48. With continued approaching motion of the housing portions, thespring 47 is compressed, as a result of which the washer-like member 46will seat firmly to the opposite side edges of the terminal 38 and 39which are in turn supported by the underlying portions of housingportion 11. Further in the relative approaching motion of the parts,plate portion 28 of housing portion 11 enters the recess 17 of thehousing portion 10 with which it has a substantially complementaryrelation, from the standpoint of configuration. In the process, studmeans 22 and 23 will pass through aligning terminal apertures 43 and thealigning lower housing apertures 31 and 32. The relative approachingmotion of the parts is continued until the flat plate-like body portions41 of the terminal members seat to the base surface of recess 17 atwhich time the plate-like portion 28 is substantially fully nestedwithin the recess 17 with stud means 22 and 23 projecting through andbeyond the plate portion 28. With the parts held in this position, theprojected extremities of stud means 22 and 23 are peened over upon theundersurface of the plate portion 28. Heating to facilitate thisprocedure may be employed or one might use a process of ultrasonicstaking or the like. As a result, the housing portions 10 and 11 arebrought to a precise assembled relation with little or no permitted lostmotion therebetween. The assembly of parts and the simplicity of theirconnection is believed obvious. The terminals 38 and 39 are accordinglytightly gripped or clamped between the housing portions to precluderelative bodily lifting or lowering motions with respect thereto andwithdrawal of the terminals is prevented by their engagement on thestuds 22 and 23. Relative angular turning motion of the terminals isprevented by the interaction thereof with the sidewalls of the recess 17and with the web segment 21. Thus the terminals are positioned in aco-planar spaced apart parallel relation. The terminals 38 and 39 have alength to project through and beyond the notches l8 and 19 to eitherside of the web segment 21. In seating within recess 17, lower housingportion ll closes the cavity 15 in the upper housing portion 10 anddefines therewith an interior chamber 40. In function the washer-likemember 46 will reciprocate with the pin 44 in such chamber. Aspreviously mentioned, marginal side portions of the terminals 38 and 39project over the mouth of the cavity and into the chamber and positionas limiting devices in the path of the washer-like member 46.

The washer-like member 46 is an electrical contact element which whencommonly seated on opposing side edgesof the terminals 38 and 39 acts asan electrical link or bridge between the terminals. The latter similarlyare electrical contacts, serving in this connection a dual function bothas terminals and as contacts. Lifting of the contact member 46 from aseat on terminals 38 and 39 disables it as a bridging member and breaksthe electrical connection between the terminals.

In the operation of the switch, the parts tend normally to assume theposition shown in FIG. 4, wherein spring 47 urges contact member 46 to aposition seated upon terminals 38 and 39. The terminals are accordinglyat this time electrically connected and tend to close any electricalcircuit in which attachment portions 42 may be connected. The pin 44 isexternally accessible and when thrust inward or upward as viewed in FIG.4 acts through its flange 45 to lift contact member 46 from terminals 38and 39. The terminals are as a consequence electronically disconnectedand the circuit of which they are a part is opened. The parts willremain so positioned as long as the inwardly thrusting pressure appliedto pin 44 continues to be applied. When such pressure is released,control of the actuator returns to spring 47 which moves the assemblycomprising the actuator pin and contact member 46 outward until thelatter again seats on the terminals 38 and 39. The making and breakingof the electrical circuit is a quick, positive action and the contactmember 46 has relatively broad engagement with the terminals 38 and 39for an easy transmission of electrical power. Spring 47 applies asubstantial pressure to the contact member for a firm seating on thecontact terminals. The housing unit comprised of housing portions 10 and11 is insulated from the flowing electrical current and protects contactmembers from the weather and from physical damage. The structure issimple to fabricate and to assemble and includes essentially but asingle moving part as represented by the actuator pin 44. Contact member46 may, in this regard, be assembled to move unitarily with the actuatorpin, as by being suitably bonded thereto. The switch because of itsrelatively few parts and simple construction may be considered anexpendable article of manufacture which in the event of damage can bereplaced as a unit.

From the above description it will be apparent that there is thusprovided a device of the character described possessing the particularfeatures of advantage before enumerated as desirable, but whichobviously is 6 susceptible of modification in its form, proportions,de-' tail construction and arrangement of parts without departing fromthe principle involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown, but that the means and construction herein disclosedcomprise but one of several modes of putting the invention into effectand the invention is therefore claimed in any of its forms ormodifications within the legitimate and valid scope of the appendedclaims.

Having thus described my invention, I claim:

1. A switch, including opposing molded plastic housing portions definingtherebetween a closed interior chamber, a pair of terminals confinedbetween said housing portions in a spaced apart relation and havingportions projecting into said chamber, an actuator slidable in one ofsaid housing portions, and means reciprocable in said chamber responsiveto movements of said actuator to occupy positions in bridging andnonbridging relation to said terminal portions, said terminals and saidlast named means constituting switch contacts, the other one of saidhousing portions having an inner face, a portion of said inner facebeing recessed, said other housing portion having a cavity opening intosaid recessed portion of said inner face, said one housing portion beingapplied in said recess in a closing relation to said cavity and definingtherewith said interior chamber, said terminals having ends received insaid recess on respectively opposite sides of said cavity and confinedin said recess by said one housing portion, said recess being open alongat least portions of the side edge of said other housing to have otherends of said terminals project therefrom.

2. A switch according to claim 1, wherein said one housing portion has abearing portion aligned with said cavity, said actuator having a slidingmount in said bearing portion with opposite ends projecting respectivelyinto said cavity and outside the switch housing as defined by saidhousing portions.

3. A switch according to claim 2, wherein said terminals are blade-likeelements adjacent edges of which project laterally to overlap peripheralportions of said cavity, said bearing portion of said one housingportion being presented in supporting relation to said adjacent edgesand an inner end of said actuator passing therebetween.

4. A switch according to claim 3, characterized in that saidreciprocable means is a washer-like element mounted to said inner end ofsaid actuator and adapted to seat on said adjacent edges of saidterminal, an inward thrusting motion of said actuator unseating saidwasher-like element.

5. A switch, including opposing molded plastic housing portions definingtherebetween a closed interior chamber, a pair of terminals confinedbetween said housing portions in a spaced apart relation and havingportions projecting into said chamber, an actuator slidable in one ofsaid housing portions, and means reciprocable in said chamber responsiveto movements of said actuator to occupy positions in bridging andnonbridging relation to said terminal portions, said terminals and saidlast named means constituting switch contacts, the other one of saidhousing portions being formed as an inverted cup with laterallyextending wing portions in rimming relation to said cup, said wingportions providing a recessed seat for said one housing portion, saidone housing portion forming with said cup said interior chamber, andstud means formed integrally with said other housing portion andprojecting through apertures in said one housing portion to establishand maintain an assembled relation of said housing portions and saidterminals.

6. A switch according to claim 5, wherein said terminals are blade-likeelements inner ends of which are received between said housing portions,said inner ends of said terminals being fixed by passage of said studsaid terminals.

1. A switch, including opposing molded plastic housing portions definingtherebetween a closed interior chamber, a pair of terminals confinedbetween said housing portions in a spaced apart relation and havingportions projecting into said chamber, an actuator slidable in one ofsaid housing portions, and means reciprocable in said chamber responsiveto movements of said actuator to occupy positions in bridging andnon-bridging relation to said terminal portions, said terminals and saidlast named means constituting switch contacts, the other one of saidhousing portions having an inner face, a portion of said inner facebeing recessed, said other housing portion having a cavity opening intosaid recessed portion of said inner face, said one housing portion beingapplied in said recess in a closing relation to said cavity and definingtherewith said interior chamber, said terminals having ends received insaid recess on respectively opposite sides of said cavity and confinedin said recess by said one housing portiOn, said recess being open alongat least portions of the side edge of said other housing to have otherends of said terminals project therefrom.
 2. A switch according to claim1, wherein said one housing portion has a bearing portion aligned withsaid cavity, said actuator having a sliding mount in said bearingportion with opposite ends projecting respectively into said cavity andoutside the switch housing as defined by said housing portions.
 3. Aswitch according to claim 2, wherein said terminals are blade-likeelements adjacent edges of which project laterally to overlap peripheralportions of said cavity, said bearing portion of said one housingportion being presented in supporting relation to said adjacent edgesand an inner end of said actuator passing therebetween.
 4. A switchaccording to claim 3, characterized in that said reciprocable means is awasher-like element mounted to said inner end of said actuator andadapted to seat on said adjacent edges of said terminal, an inwardthrusting motion of said actuator unseating said washer-like element. 5.A switch, including opposing molded plastic housing portions definingtherebetween a closed interior chamber, a pair of terminals confinedbetween said housing portions in a spaced apart relation and havingportions projecting into said chamber, an actuator slidable in one ofsaid housing portions, and means reciprocable in said chamber responsiveto movements of said actuator to occupy positions in bridging andnon-bridging relation to said terminal portions, said terminals and saidlast named means constituting switch contacts, the other one of saidhousing portions being formed as an inverted cup with laterallyextending wing portions in rimming relation to said cup, said wingportions providing a recessed seat for said one housing portion, saidone housing portion forming with said cup said interior chamber, andstud means formed integrally with said other housing portion andprojecting through apertures in said one housing portion to establishand maintain an assembled relation of said housing portions and saidterminals.
 6. A switch according to claim 5, wherein said terminals areblade-like elements inner ends of which are received between saidhousing portions, said inner ends of said terminals being fixed bypassage of said stud means therethrough.
 7. A switch according to claim6, wherein the said wing portions on the other one of said housingportions form a plate portion, said inverted cup having an outer wallsurface substantially coincident at one point with one edge of saidplate portion and including an arcuate segment producing a projection atthe opposite edge of said plate, said arcuate segment being formed withnotches accommodating projection therethrough of said terminals.